By BRETT PULLEY

Published: September 18, 1996

NEWARK, Sept. 17—
The Republican National Committee is broadcasting advertisements denouncing Representative Robert G. Torricelli, the Democratic candidate for Senate in New Jersey, as ''liberal and wrong.'' The ads make no mention of the Republican candidate, Representative Richard A. Zimmer, or the November election, and that is no accident.

The careful wording of the script keeps the hundreds of thousands of dollars that the ads cost exempt from Federal Election Commission spending limits.

Money from the national Republican Party is lighting up televisions in New Jersey and other states with close Senate races. In Rhode Island, for instance, where Representative Jack Reed, the Democratic candidate, is facing the Republican Nancy J. Mayer for one of 14 open Senate seats in the nation, the Republican National Committee paid for advertisements that call Mr. Reed ''ultra-liberal'' and ''desperate.''

The ads are officially billed as ''issues oriented,'' and under Federal election rules cannot advocate the election or defeat of a candidate. But in practice, the ads are as attacks on the candidate who is opposed by the organization paying for the ads -- whether it is the Republican National Committee, the A.F.L.-C.I.O. or an environmental group.

These ads are not a new phenomenon, but a series of recent court decisions have paved the way for a significant expansion of their use this year, both in Congressional racesand in the Presidential campaign. For a candidate like Mr. Zimmer, whose campaign war chest is substantially smaller than Mr. Torricelli's, the ads serve several purposes. They attack, and possibly weaken, Mr. Torricelli.

Mr. Zimmer does not have to pay, and they do not count against his campaign spending limits.

''There's been a real explosion of so-called issue ads, which are basically designed to avoid the Federal election laws,'' said Donald Simon, executive vice president of Common Cause, a citizen group that works for changes in campaign finance laws. ''This is a form of cheating.''

David P. Rebovich, a political science professor at Rider University, had a similar assessment: ''This is a new way that money is having influence. It seems to be highly effective, and both parties are doing it.''

Critics also say the ads are a direct threat to campaign spending laws that limit the use of big donations from corporations and wealthy individuals for Federal elections. While donations to particular candidates are strictly limited, corporations can give as much as they want for ''party building'' activities.

As Mr. Torricelli asserted, ''It's entirely negative and largely paid for out of corporate funds.'' But Mr. Torricelli himself is no innocent victim. Although the Democratic National Committee, which is not nearly as well financed as its Republican counterpart, has not yet broadcast similar ads, Mr. Torricelli and other Democratic candidates have benefited from ads bought on their behalf by special-interest groups.

The A.F.L.-C.I.O., for example, is running ads around the country criticizing Republican Congressional candidates. And a radio ad paid for by New Jersey Citizen Action, a consumer and environmental group, accuses Mr. Zimmer of taking money from ''corporate polluters.'' The ad does not mention Mr. Torricelli and therefore does not count against his spending limit.

''When any reasonable person looks at these ads, they see them as helping a candidate and influencing the election,'' Mr. Simon said.

At a news conference last week, Mr. Torricelli, referring to the advertisements, said, ''The sleaziest campaign in the history of New Jersey has just begun.''

In one of the most recent ads broadcast by the Republican committee, Mr. Torricelli is characterized as a ''big spender'' who voted for the largest tax increase in history and for a $35,000 pay raise.

But both candidates seem to be tossing equal amounts of mud. As they enter the last seven weeks of the campaign, the race has become largely defined by the daily barrage of mostly specious charges, as the two candidates throw an endless supply of allegations at the news media, hoping something sticks.

The advertisements fall into two categories. ''Issue-oriented,'' or ''voter education,'' advertisements are permitted as long as they address a single issue, they make no mention of an election and the group paying for the advertisement shows no signs of having coordinated the advertising effort with the candidate. These advertisements are paid for with the big corporate donations, generally known as ''soft money.''

The second category, ''independent expenditure'' advertisements, are a direct result of a United States Supreme Court ruling in June that struck down Federal limits on the amount that party organizations can spend on a candidate's behalf. Under the new guidelines, a political party can spend as much as it chooses to advocate the election or defeat of a candidate as long as the expenditure is not coordinated with the candidate's campaign. For these ads, the party cannot use soft money.